Fiber glass ski with channel construction



March 31, 1970 K, @SCHMIDT m1 3,503,621

FIBER GLASS SKI WITH CHANNEL CONSTRUCTION Filed May 8. 1968 FIG-3ATTORNEYS United States Patent O 3,503,621 FIBER GLASS SKI WITH CHANNELCONSTRUCTION Klaus D. Schmidt, San Francisco, and Merritt A. Robinson,San Anselmo, Calif., assignors to Kimball-Schmidt, Inc., San Rafael,Calif., a corporation of California Filed May 8, 1968, Ser. No. 727,569Int. Cl. A63c 5/12 U.S. CI. 280-1L13 1 Claim ABSTRACT OF THE DISCLOSUREA fiber glass ski having two lengthwise members at least one of whichhas a molded-in camber and a U-shaped channel construction, the skibeing filled with a plastic foam material. When both members areprovided with a U-shaped channel construction the members are telescopedtogether. Steel edges can be inserted along the length of the ski withportions of said edges being disposed between the telescoped side wallsof the ski members.

BACKGROUND OF THE INVENTION At present, fiber glass skis are beginningto come into relatively wide usage. However, to the best of applicantsknowledge all of such skis are made by laminating a core material andupper and lower ber glass shell members.

One of the most common problems with such skis is that of delamination.During normal use a ski must flex from tip to tail, placing thelaminated interfaces of the skis in longitudinal shear. In manyinstances, the repeated flexing'will cause the ski to fail along theplanes of lamination.

Additionally, the laminated construction presently used makes itdifficult to control the degree of camber which the finished ski is tohave. Even though the individual layers of the ski will be formed with adesired amount of camber in each, when all are assembled together thefinal camber will not always be precisely that which is desired.

Further, all snow skis are provided with steel edge members along thelength thereof, such members being generally fastened by screws to theski. These edges are subjected to high horizontal forces tending to pullthem sideways from the ski and edge failures have proven troublesome.

SUMMARY OF THE INVENTION The above problems of fiber glass skis havebeen solved by the present invention in several ways.

First of all, instead of utilizing the usual lamination-of flat layersof fiber glass and core material, applicants form a lower ski member ofa single piece of fiber glass material having a generally U-shapedconstruction throughout its length, so that the side walls of the lowerski member also form the side walls of the ski. The top of the ski isthen enclosed by an upper member which is bonded to the side walls ofthe lower member, thus forming an elongated box, in which the corematerial is disposed.

`The shear load in the ski is then taken up by the four corner edges ofthe ski and the extensive contact area between the two laminates, all ofwhich are integral with the lower ski member, thus reducingsubstantially the failure of the ski from normal fiexure during use.

In addition, the fact that the side walls of the ski are integral withthe bottom surface enables the camber to be accurately retained aftermolding, since the side walls will resist the tendency of the bottomsurface to flatten out after molding.

3,503,621 Patented Mar. 31, 1970 ICC The advantages above can beenhanced by molding both the upper and lower members so that they have alengthwise channel construction. The members are telescoped together andthe side walls bonded together along their length. With suchconstruction there is no lengthwise plane of the ski in whichflexure-induced shear stresses are imposed upon bonded interfaces alone.

The double channel construction has a further advantage in that itenables steel edge members to be inserted between the telescoped sidewalls of the ski members. The edge members are thus held from pullingaway from the ski by the basic structure of the ski rather than merelyby screws or other bonding means.

Other objects and advantages will become apparent in the course of thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, forming a part ofthis application, and in which like parts are designated by likereference numerals throughout the same,

FIG. l is a side elevation of a ski embodying the principles of thisinvention;

FIG, 2 is a plan view of a ski as shown in FIG. 1;

FIG. 3 is a cross-sectional view of the ski of FIG. l, taken on line 3-3thereof;

FIG. 4 is a cross-sectional view of the ski of FIG. 1, taken on line 4-4thereof;

FIG. 5 is a cross-sectional view, similar to FIG. 4, showing anotherembodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings,and particularly to FIGS. 1-4 thereof, FIG. 1 illustrates a side view ofthe ski 10 having a tip or shovel portion 11 and a tail portion 12. Asis conventional, the shovel portion curves upwardly and forwardly frompoint 13 and the ski is curved upwardly from point 13 to the tail togive the ski its desired and necessary camber.

The body of the ski 10 is comprised primarily of three elements: thelower ski member 14, the core 15 and upper ski member 16. As is shown inFIGS. 3 and 4, the lower ski member has a running portion 17, andupstanding side walls 18 and 19 which run throughout the length of theski, thus forming a generally U-shaped channel. The upper ski member 16has an upper portion 21 and downwardly depending side walls 22 and 23,thus forming a generally inverted U-shaped channel which runs throughoutthe length of the ski.

The ski is built up as follows. A mold (not shown) having the outsideconfiguration of the lower ski member is utilized, the mold being formedto provide the proper camber for the ski, such camber beingpredetermined by wellknown techniques. A sole piece 24, of Teflon,polyethylene or similar material is first placed in the bottom of themold cavity to extend the length thereof. A mat of interwoven glassfibers is then placed i in the mold cavity, such mat extendingthroughout the length of the mold, to form the running portion 17 andside walls 18 and 19 of the lower ski member. A layer of fiber glassrovings 25 is then disposed in the mold cavity with the rovings runningfrom one end to the other of the mold. A thermossetting resin, such as apolyester or an epoxy resin, is applied in a conventional manner toimpregnate the fiber glas material in the mold. An inner mold member(not shown) is moved into the mold cavity and heat and pressure isapplied, in a conventional manner, to the materials in the mold, withsuch heat and pressure being applied for a length of time suficient toset the resin and bond the sole piece 24 to the lower ski member 14.

The upper ski member 16 is formed in the same manner. A fiber glass matis placed in the mold cavity of a mold having a cavity shape conformingto the outer shape of the upper ski member and having a cambercomplementary to that of the lower ski member. The ber glass mat extendsthe full length of the mold cavity. Next, a layer of fiber glass rovings26 is disposed in the cavity with the rovings running the length of themold. A thermosetting resin is applied to impregnate the liber glassmaterial and heat and pressure is applied to set the resin.

The channel formed by the lower ski member 14 is then lled with asuitable plastic foam, such as an epoxy or polyurethane foam. Preferablythis is sprayed in as a liquid and after a relatively short time it willharden into a solid core of foam material 15.

The lower ski member 14 thus formed is a one-piece member having thedesired channel construction and predetermined camber molded thereinto.The side walls thereof will resist any tendency of the camber to changesince they are interal with and perpendicular to the running portion ofthe ski member.

The foam core 15 may now be routed out to enable the solid plastic llers29 and 30 to be inserted in the channel of the lower ski member toachieve the desired thickness at the tip and tail of the ski. Such llersmay be made of ABS, nylon, polypropylene, or the like. Preferably thefiller 29 will extend from the tip 11 of the ski to about 10-12 inchesthereform, and the ller 30 will extend from the tail 12 of the ski toabout 8 inches therefrom. If desired, such filler coud be put into thelower ski member channel before the foam core is put thereinto.

Suitable bonding material, such as an epoxy, is applied to the outersurfaces of the side walls 18 and 19 of the lower ski member 14 and/orto the inner surfaces of the side walls 22 and 23 of the upper skimember 16, and the upper ski member is telescoped onto the lower skimember, as shown in FIGS. 3 and 4. A hardened edge member 311 preferablyof steel, having an L-shaped configuration, is attached to the ski Ibyinserting the upstanding flange portion 32 between the side walls 19 and23 of the ski members 14 and 16. The edge member is bonded to the sidewalls by the bonding material thereon. Edge member 33 is similarlyattached to the other side of the ski.

FIG. illustrates an embodiment of the invention wherein only the lowerber glass ski member 114 of ski 110 is formed with side walls 118 and119 integral with the portion 117 to form a U-shaped channel. The lowerski member 114 is formed with a sole piece 124 and layer of fiber glassrovings 125 in the same manner as previously described. Similarly, theplastic foam core 115 is formed in the same manner. The upper liberglass ski member 116 encloses the channel formed by the lower ski memberand is bonded to the tops of the side walls 118 and 119 by a suitablebonding agent. Hardened edge members 131 and 133 are attached to the skiin any conventional manner.

With the foregoing ski construction, it has been found that suchconstruction easily enables the channels to be made as thick or thin asdesired, or to vary the thickness along the length of the channels so asto provide the lbest ilexibility of the ski, without varying the overallexterior dimension of the ski, to enable such skis to be best adapted tothe particular use to which they will be put. This advantage isextremely diicult to achieve with any degree of precision in thestandard laminated ski construction.

Due to the box construction of the channel-shaped members, the camber ofthe ski is locked in and is independent of any possible creep of thecore material. Also, as previously pointed out, the shear stresses onthe `ski will be resisted by the integral side walls of thechannelshaped members so that lamination peelis eliminated. Particularlyis this true with the double channel construction, since at nolongitudinal plane is shear stress resisted solely yby interfacelaminations. Also with the double channel construction the steel edgescan be securely locked into place, since they are held against outwardmovement by the structural side walls 22 and 23 of the upper ski member16.

Having thus described our invention, we claim:

1. A ski comprising: A

(a) a lower ski member formed of ber glass material impregnated with aset resin, said lower ski member having a lower running portion andupwardly extending side walls to form a generally U-shaped channelsubstantially throughout its length, and said lower ski member having apredetermined camber molded thereinto along its length;

(b) an upper ski member formed of -ber glass material impregnated with`a set resin, said upper ski member having an upper portion anddownwardly extending side walls substantially throughout its length,said upper ski member having its side walls telescoped onto and bondedto the side walls of said lower ski member;

(c) a core of synthetic foam material lling said channel formed by saidlower ski member;

(d) solid plastic ller members disposed between the upper portion ofsaid upper ski member and running portion of said lower ski memberadjacent the tip and tail of said ski.

References Cited UNITED STATES PATENTS 2,484,141 10/1949 Alex. 2,613,66010/1952 Bear. 2,694,580 11/1954 Head. 3,208,761 9/1965 Sullivan et al.

FOREIGN PATENTS 220,991 4/1962 Austria. 1,435,153 3/1966 France.

U.S. Cl. X.R. l6l-l56, 159, 170

LEO FRIAGLIA, Primary Examiner MILTON L. SMITH, Assistant Examiner

